Various techniques to control the validity of a touch operation on a certain region have been proposed. For example, a technique to perform such control as to determine, in response to detection of a first touch operation on a particular region and a second touch operation on a region other than the particular region on a touchscreen, that the first touch operation is invalid and the second touch operation is valid is known. (See, for example, Japanese Laid-open Patent Publication No. 2013-196582.)
Furthermore, for example, a technique to determine, using a first region and a second region greater than the first region, that the first region is depressed in response to determining that a finger is within the second region when leaving the first region after depressing the first region is known. (See, for example, Japanese Laid-open Patent Publication No. 11-175212.)